Metal working tool



Sept. 27, 1932. w. c. SPROUL METAL WORKING TOOL Original Filed May 3, 1930 Inc/en ror WGSP O UL flrrom ey Patented Sept. 27, 1932 UNITED PATENT! .orrla'cifi 1 WILLIAM C. SPROUL, or "Rookro'np, ILLINoIs-hssIGNoR To rnE NeEnsoLL MILLING MACHINE COMPANY, or ROCKFORD, ILLINOIS, A CORPORATION or ILLINoIs 1 METAL WORKIN TOOL I Original application filed Hays, 1930;Seri al No.'449,42 5. Divided and this applieation l filed January 1981. Serial This application is a division of application serial number 449,425 filed May 3rd, 1930.

The present invention relates in genera-lto metal working toolsandhas particular reference to that type of tool in which one or more inserted cutter teeth are rigidly anddetachably secured in a rotary head, bar or the like mounting. r I

The application of the invention in the present instance is shown inconnection with a milling cutter ofthe face mill. type. Fre quently these cutters are referred to in trade as cone head cuttersdue to theifrustum shape of the head. I 1

One difliculty in seeking a practical solution of the problems involved in the production of these types of cutters is concerned primarily in holding the teeth rigidly in an open-ended slot and at the same. time allowing for adjustment of the teeth in a direction parallel with the axis of the head. Many solutions have been suggested such as interlocking the teeth in the head slots by the use of serrations, sometimes formed in the Walls of the head slots and in the teeth themselves. In other instances, the use of shoes, keys and the like accessories have been employed. The use of such accessories is not to be tolerated if it is at all possible to get along without them because they add to the cost of produc tion and are theoretically wrong. 'One of the important objects of the present invention is to provide means such as serrations or the like for interlocking the teeth in the slots of the head and to place these serrations in the base of the slot where they are most needed, without the aid of such accessories as shoes, keys or the like.

Briefly, the salient feature of the invention resides in providing serrations in the base of a tooth slot in a milling cutter or the like head with the serrations extending at an angle to the longitudinal axis of the slot and to equip the cutter tooth with serrations on its underside to interlock with the serrations thus provided for in the base of the slot.

It is not uncommon to cut serrations in the base of a slot in a milling cutter head when the serrations extend longitudinally or parallelwith the axis of the head but. to produce these serrations crosswise at an angle to the longitudinal axis of the slot is entirely adifferent matter. It is only after exercising considerable inventive ingenuity that it has been possible to-devise amethod of producing the serrations in the base of the .slot at an angle to the longitudinal axis of the slot.

WVhile the foregoing statement is. indicative in a general way of the nature of the inw vention other objects andadvantages will be apparent upon a full understanding'of the construction and co-operative relationship of, the several parts of the tool.

One form of the. invention is. presented herein by way. of exemplification but it will of course be. understood that the invention is. susceptible of embodiment in still other structural modified I forms without depart-.

ing'from'the spirit ofthe invention as definedin the sub-joined claims.

In the accompanying drawing:

Fig.1 is..a view in perspectiveiof a .por-. tion ofamilling cutter, showing one application-of the-present invention;

- "Flgl'2 isa top: plan view. ofaportionof a milling cutter, showing the application of the invention Fig; 3 is a view in the: line 3 -3,Fig. 2;

Fig. 4 is a detailed'view. inside elevation, of a portion of a. milling cutter head, illustrating the method of reducing the present. inventionto practise;

cross section, taken .on'

Fig; 5is1adetailed perspective View of a. 85,,

cutter tooth made lIlfiCCQIdELIlCB with the in vention; and. r a l r Fig. dis a detailperspective view of the invention as used'in. connection with a wedge type of holding means. Y Y Sincethe invention is 'especially adapted for use inconnectionwith inserted-tooth milling cutters this .particularuse has been selected in the accompanying drawin and in which part5'represents'a portion 0% cutter head the same having a=plurality o circumferencially spaced slots for the reception of the inserted cutter teeth 6. These teeth are rigidly and detachably fastened'in a milling 5 the slots byclamping heads] which are made In to-straddle each of a pair of teeth. Each of the clamping heads 7 is made with a tapped hole into which is threaded the end 8 of a bolt 9. The bolt is inserted through a hole which is drilled through the head 5 from the outer to the inner circumference. The hole is also countersunk to accommodate the head 10 of the bolt which in turn is made with a key socket 11 so that the'bolt may be turned to release or tighten the clamping heads 7 In addition to the clamping device for rigidly and detachably holding the teeth in the'slots. additional means isemployed to co-operate therewith. In this connection at-;

tention is now invited to the serrations on the bottom of the teeth and in the base of the head slots; These serrations according to the present invention are preferablymade on the order of threads. The reason for which will be hereinafter explained.

Qextend at 'an angle to the longitudinal axis of the slot without the use of shoes, keys or the like. In reducing the inventionto practice a series of holes 12 are drilled through the thickness of the head 5 at spaced intervals around the same. The holes being. then tapped, as shown in dotted lines in Fig. 4,

then the metal between the dotted'lines 14 is cutaway to leave the slots, the result be ing a slot with half-threads or thread like serrations in the base thereof. The cutter teeth 6 are serrated across the bottom to leave halfthreads corresponding to the thread like ser- In this divisional application the serrated structure of the assembly is covered, whereas in the parent application of which this is a division the method of producing the serrations is claimed.

Having'thus described and shown an embodiment of this invention, what I claim and desire to secure by Letters Patent of the United States is: I

' 1. In an inserted tooth metal working tool the combination of a slotted head having helical half-threads formed in the base of the'slot thereof and a cutter tooth for said slot having mating helical half-threads on its underside to interlock with the helical halfthreads in the base of the head slot, and means for rigidly and detachably holding the tooth inthe slot.

2. The combination as set forth in claim 1 and in which the width of the head slot is less than the diameterof the root of the threads in the base of said slot.

3. In an inserted tooth metal working tool the combination of a slotted head having helical half-threads formed in the base of the slot thereof and a cutter tooth for said slot having mating helical half-threads on its underside to interlock with the helical halfthreads in the base of the head slot, and means for rigidly and detachably holding the tooth in the slot,'comprising clamping means'engaging the top side of the tooth.

Signed at Rockford, in the county of WVinnebago, and State of Illinois, this 31st day of December, 1930.

WILLIAM C. SPROUL.

rations in the base of the slots. The thread like serrations on the bottom of the teeth merge into the sides of the teeth and correspond to the thread like'serration in the bottom of the slots and in this connection it should be pointed out that the width of the slots should be less than the diameter of the root of the threads tapped as at 13 to properly accommodate the'teeth. without lost mo- :tion.

A cutter assembly constructed in. accordance with the-present inventionprovides an unusually convenient means of adjusting the teeth parallel or substantially parallel with the axis of the head and also avoids any pos-v sibility of the teeth moving in the-slots in a direction parallel or substantially parallel with the axis of the head. r

In Fig. 6'the serrations are shown in connection with a wedge type of holding means. 

